 They include several buildings known as "blocks" which can consist of more than one adjacent and attached structure, as is the case with the Waterman Block, one of the Sycamore commercial buildings.Possibly the gem of the Sycamore Historic District is the DeKalb County Courthouse.The Courthouse sits in the center of a square facing Illinois Route 64, directly across the north/south street, Main, from the Sycamore Public Library.